1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (C) 2019 Arm Ltd. |
3 | * |
4 | * Based on msm_gem_freedreno.c: |
5 | * Copyright (C) 2016 Red Hat |
6 | * Author: Rob Clark <robdclark@gmail.com> |
7 | */ |
8 | |
9 | #include <linux/list.h> |
10 | |
11 | #include <drm/drm_device.h> |
12 | #include <drm/drm_gem_shmem_helper.h> |
13 | |
14 | #include "panfrost_device.h" |
15 | #include "panfrost_gem.h" |
16 | #include "panfrost_mmu.h" |
17 | |
18 | static unsigned long |
19 | panfrost_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) |
20 | { |
21 | struct panfrost_device *pfdev = shrinker->private_data; |
22 | struct drm_gem_shmem_object *shmem; |
23 | unsigned long count = 0; |
24 | |
25 | if (!mutex_trylock(lock: &pfdev->shrinker_lock)) |
26 | return 0; |
27 | |
28 | list_for_each_entry(shmem, &pfdev->shrinker_list, madv_list) { |
29 | if (drm_gem_shmem_is_purgeable(shmem)) |
30 | count += shmem->base.size >> PAGE_SHIFT; |
31 | } |
32 | |
33 | mutex_unlock(lock: &pfdev->shrinker_lock); |
34 | |
35 | return count; |
36 | } |
37 | |
38 | static bool panfrost_gem_purge(struct drm_gem_object *obj) |
39 | { |
40 | struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); |
41 | struct panfrost_gem_object *bo = to_panfrost_bo(obj); |
42 | bool ret = false; |
43 | |
44 | if (atomic_read(v: &bo->gpu_usecount)) |
45 | return false; |
46 | |
47 | if (!mutex_trylock(lock: &bo->mappings.lock)) |
48 | return false; |
49 | |
50 | if (!dma_resv_trylock(obj: shmem->base.resv)) |
51 | goto unlock_mappings; |
52 | |
53 | panfrost_gem_teardown_mappings_locked(bo); |
54 | drm_gem_shmem_purge(shmem: &bo->base); |
55 | ret = true; |
56 | |
57 | dma_resv_unlock(obj: shmem->base.resv); |
58 | |
59 | unlock_mappings: |
60 | mutex_unlock(lock: &bo->mappings.lock); |
61 | return ret; |
62 | } |
63 | |
64 | static unsigned long |
65 | panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) |
66 | { |
67 | struct panfrost_device *pfdev = shrinker->private_data; |
68 | struct drm_gem_shmem_object *shmem, *tmp; |
69 | unsigned long freed = 0; |
70 | |
71 | if (!mutex_trylock(lock: &pfdev->shrinker_lock)) |
72 | return SHRINK_STOP; |
73 | |
74 | list_for_each_entry_safe(shmem, tmp, &pfdev->shrinker_list, madv_list) { |
75 | if (freed >= sc->nr_to_scan) |
76 | break; |
77 | if (drm_gem_shmem_is_purgeable(shmem) && |
78 | panfrost_gem_purge(obj: &shmem->base)) { |
79 | freed += shmem->base.size >> PAGE_SHIFT; |
80 | list_del_init(entry: &shmem->madv_list); |
81 | } |
82 | } |
83 | |
84 | mutex_unlock(lock: &pfdev->shrinker_lock); |
85 | |
86 | if (freed > 0) |
87 | pr_info_ratelimited("Purging %lu bytes\n" , freed << PAGE_SHIFT); |
88 | |
89 | return freed; |
90 | } |
91 | |
92 | /** |
93 | * panfrost_gem_shrinker_init - Initialize panfrost shrinker |
94 | * @dev: DRM device |
95 | * |
96 | * This function registers and sets up the panfrost shrinker. |
97 | */ |
98 | int panfrost_gem_shrinker_init(struct drm_device *dev) |
99 | { |
100 | struct panfrost_device *pfdev = dev->dev_private; |
101 | |
102 | pfdev->shrinker = shrinker_alloc(flags: 0, fmt: "drm-panfrost" ); |
103 | if (!pfdev->shrinker) |
104 | return -ENOMEM; |
105 | |
106 | pfdev->shrinker->count_objects = panfrost_gem_shrinker_count; |
107 | pfdev->shrinker->scan_objects = panfrost_gem_shrinker_scan; |
108 | pfdev->shrinker->private_data = pfdev; |
109 | |
110 | shrinker_register(shrinker: pfdev->shrinker); |
111 | |
112 | return 0; |
113 | } |
114 | |
115 | /** |
116 | * panfrost_gem_shrinker_cleanup - Clean up panfrost shrinker |
117 | * @dev: DRM device |
118 | * |
119 | * This function unregisters the panfrost shrinker. |
120 | */ |
121 | void panfrost_gem_shrinker_cleanup(struct drm_device *dev) |
122 | { |
123 | struct panfrost_device *pfdev = dev->dev_private; |
124 | |
125 | if (pfdev->shrinker) |
126 | shrinker_free(shrinker: pfdev->shrinker); |
127 | } |
128 | |